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Query: UMLS:C0014118 (endocarditis)
 15,629 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Thrombin-induced platelet microbicidal protein (tPMP) is secreted by rabbit platelets following thrombin stimulation, and it kills common endovascular pathogens in vitro, including Staphylococcus aureus. Therefore, pathogens which exhibit tPMP resistance in vitro possess a potential survival advantage in vivo at sites of endovascular damage. We generated an isogenic S. aureus strain pair, differing in tPMP susceptibility, by transposon (Tn551) mutagenesis of a tPMP-susceptible (tPMPs) parental strain (ISP479) to derive a stably tPMP-resistant (tPMPr) strain, ISP479R. ISP479 and ISP479R were equivalent in vitro in the following phenotypes: biotyping, antiobiograms, platelet adherence and aggregation, growth kinetics, cell wall-associated protein A expression, and fibrinogen binding. Genotypic comparisons of chromosomal DNA of strains ISP479 and ISP479R following restriction endonuclease digestion revealed indistinguishable pulsed-field gel electrophoretic patterns. The genotype exhibited by strain ISP479R was linked to the tPMP-resistant phenotype, as it was transducible into the initially tPMP-susceptible parental strain, ISP479. Southern hybridization verified the presence of a single copy of Tn551 in the same chromosomal restriction site of both ISP479R and tPMPr transductants of ISP479. The correlation of in vitro tPMP susceptibility phenotypes with the ability to induce experimental endocarditis (a prototypical endovascular infection) was evaluated. Despite equivalent rates of endocarditis induction, animals infected with strain ISP479R achieved significantly higher vegetation bacterial densities over a 7-day post-challenge period than did animals infected with strain ISP479. These data suggest that tPMPr microbial strains have a selective advantage in experimental staphylococcal endocarditis. Furthermore, the major impact of tPMP resistance upon endocarditis pathogenesis appears to involve a postvalvular adherence event(s), most probably by facilitating bacterial proliferation within vegetations.
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PMID:Phenotypic resistance to thrombin-induced platelet microbicidal protein in vitro is correlated with enhanced virulence in experimental endocarditis due to Staphylococcus aureus. 923 89

Candida parapsilosis, an important nosocomial pathogen and the most common species of Candida found on the hands of health care workers, is a rare cause of prosthetic valve endocarditis (PVE). From March through June 1994, four cases of C. parapsilosis PVE were diagnosed at a 400-bed community hospital. The mean time to presentation after valve replacement surgery was 148 days (range, 20 to 345). Three of the four patients died of complications of PVE. Multiple environmental cultures were performed, and only one was positive for C. parapsilosis. Cultures from the bypass pump, cell saver, cardioplegia solution, and subsequent valves were all negative. All valve replacements were performed by the same operating room team. Interviews with the surgeon and physician assistant, the only personnel involved in all cases, revealed that their hypoallergenic gloves were subject to frequent tears during valve replacement procedures, often requiring several glove changes per procedure. Hand cultures of personnel were obtained, and cultures from 20 individuals (26%) were positive for C. parapsilosis. Hand cultures of the surgeon and physician assistant obtained 8 months after the last case had surgery were negative for yeasts. Molecular typing of the 3 available case isolates, 14 epidemiologically unrelated patient isolates, 1 environmental isolate, and 20 hand isolates was performed by electrophoretic karyotyping and restriction endonuclease analysis of genomic DNA using restriction enzymes BssHII and EagI followed by pulsed field gel electrophoresis. The three case isolates were identical by restriction endonuclease analysis of genomic DNA, and two of the three shared the same electrophoretic karyotyping profile. The remaining patient, environmental, and hand isolates represented 29 different DNA types and were distinctly different from the case isolates. All of the isolates tested were susceptible to amphotericin B, 5FC, fluconazole, and itraconazole. The circumstantial evidence suggests the probability of glove tears during valve replacement surgery and subsequent transmission of C. parapsilosis to patients.
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PMID:An outbreak of Candida parapsilosis prosthetic valve endocarditis. 940 7

Bartonella vinsonii subsp. berkhoffii was originally isolated from a dog suffering infectious endocarditis and was recently identified as a zoonotic agent causing human endocarditis. Following the coyote bite of a child who developed clinical signs compatible with Bartonella infection in Santa Clara County, Calif., this epidemiological study was conducted. Among 109 coyotes (Canis latrans) from central coastal California, 31 animals (28%) were found to be bacteremic with B. vinsonii subsp. berkhoffii and 83 animals (76%) had B. vinsonii subsp. berkhoffii antibodies. These findings suggest these animals could be the wildlife reservoir of B. vinsonii subsp. berkhoffii. PCR-restriction fragment length polymorphism (PCR-RFLP) analysis of the gltA and 16S rRNA genes for these 31 isolates yielded similar profiles that were identical to those of B. vinsonii subsp. berkhoffii. Partial sequencing of the gltA and 16S rRNA genes, respectively, indicated 99.5 and 100% homology between the coyote isolate and B. vinsonii subsp. berkhoffii (ATCC 51672). PCR-RFLP analysis of the 16S-23S intergenic spacer region showed the existence of two different strain profiles, as has been reported in dogs. Six (19%) of 31 Bartonella bacteremic coyotes exhibited the strain profile that was identified in the type strain of a canine endocarditis case (B. vinsonii subsp. berkhoffii ATCC 51672). The other 25 bacteremic coyotes were infected with a strain that was similar to the strains isolated from healthy dogs. Based on whole bacterial genome analysis by pulsed-field gel electrophoresis (PFGE) with SmaI restriction endonuclease, there was more diversity in fingerprints for the coyote isolates, which had at least 10 major variants compared to the two variants described for domestic dog isolates from the eastern United States. By PFGE analysis, three Bartonella bacteremic coyotes were infected by a strain identical to the one isolated from three healthy dog carriers. Further studies are necessary to elucidate the mode of transmission of B. vinsonii subsp. berkhoffii, especially to identify potential vectors, and to determine how humans become infected.
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PMID:Coyotes (Canis latrans) as the reservoir for a human pathogenic Bartonella sp.: molecular epidemiology of Bartonella vinsonii subsp. berkhoffii infection in coyotes from central coastal California. 1106 89

Peptostreptococcus magnus is the most pathogenic and one of the most common Gram-positive anaerobic cocci found in human clinical specimens. The organism has been isolated in pure culture from a range of serious infections, including meningitis and endocarditis. However, isolation of Peptostreptococcus magnus from the oral cavity has rarely been attempted. Identification of Peptostreptococcus magnus in clinical specimens is reliant upon microbiological culture and biochemical methods, which often give ambiguous results. The aim of this study was to develop a PCR assay for the specific detection of Peptostreptococcus magnus in oral clinical specimens. PCR primers specific for Peptostreptococcus magnus DNA were derived by comparison of 16S rRNA gene sequences and selection of primers that demonstrated specificity at their 3' ends for Peptostreptococcus magnus. PCR positivity for Peptostreptococcus magnus DNA was indicated by the amplification of a 553 bp product. The PCR assay was then used to attempt detection of Peptostreptococcus magnus DNA in subgingival plaque samples from adult periodontitis patients and pus aspirates from subjects with acute dento-alveolar abscesses. The PCR assay was demonstrated to be highly specific for Peptostreptococcus magnus DNA, since no PCR products were obtained when genomic DNA from a wide range of other oral bacteria, including closely related Peptostreptococcus species, was used in the PCR assay. Confirmation of specific amplification of Peptostreptococcus magnus DNA was obtained by digestion of PCR products with the restriction endonuclease RsaI, which gives a unique restriction profile for Peptostreptococcus magnus. Of the 33 subgingival plaque samples analysed, 2 (6 %) were positive for Peptostreptococcus magnus DNA. None of the 60 pus aspirates analysed was positive for Peptostreptococcus magnus DNA. It is concluded that Peptostreptococcus magnus is not a major pathogen in adult periodontitis or dento-alveolar abscesses. The PCR assay provides a more rapid, specific and sensitive alternative to conventional methods for identification of Peptostreptococcus magnus in clinical specimens.
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PMID:Specific PCR detection of Peptostreptococcus magnus. 1267 69

The present study proposed use of modified multilocus sequence typing (MLST) approach, for subspecies differentiation of Enterococcus faecalis isolates. We disgesed with SspI endonuclease product of amplification of three E. faecalis antigen-encoding genes (ace, encoding a collagen and laminin adhesin; efaA, encoding an endocarditis antigen; and salA, encoding a cell wall associated antigen) and one housekeeping gene (pyrC) of 32 E. faecalis isolates MLRA analysis of polymorphic regions of these four genes identified 23 distinct types 21.4 to 100% identity among the 32 isolates. Further studies are needed to evaluate the value of proposed method.
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PMID:[The use of Multiplex PCR-RFLP method (multilocus RFLP) in identification and differentiation of enterococci]. 1554 84


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